new pumped shower but where's my hot water?

Talon.ie

I just had a new bathroom fitted, new sinks, shower, heated towell rail. Basically lots of plumming.

When we were getting this done we decided we wanted to increase the water pressure to the shower, so the plummer added a pump in the hotpress.

The pressure isn't a problem, but the hot water isn't lasting very long. Previously you'd have hot water for about 20-30 minutes worth of showering (some of us like long showers!). We'd never really have to use the immersion as the water was heated by the gas boiler when the heating comes on in the morning

Now the hot water runs out after 4 minutes. The odd thing is that there's still hot water in the sink in the bathroom, so we're not using up all the hot water

I'd expect us to get through the hot water more quickly after the pump was added, but I was expecting it to last 10-15 minutes (1/2 as long), but 4 minutes seems ridiculous.

The plummer has had a look and doesn't seem to know what to do. He suggests we run the immersion each morning, but this doesn't seem practical (or cost effective)

Am I wrong to expect the water to last longer than 4 minutes? Or am I getting the run around from the plummer?

Davy

To hard to tell yet without more into.

If you can post the model of the pump, the flow rate can be gotten.

When you say their is still hot water in the taps, have you ran it for awhile, that its not whats just sitting in the pipework run from the cylinder. If it still hot after 60 seconds, then you still should have hot water in the shower.

Is the shower mixer plumbed correctly? You can get similar effects with no hot/ or too hot with crossed supply's.

Whats your cylinder stat set to if you have one?
How long is the boiler being called for hot water?

Joey the lips

I am guessing the plumber used a warrick/surrey flange and the reason your running out of hot in the pump and not the taps is there is about 5 ltrs left in the taps.

Out side that more info.

Sparkpea

surrey flange will draw the hot water out of the tank about 6" below the connection so like joey said thats why ur getting hot water at the taps but not the shower, using a surrey flange is the correct method as well, thumbs up to the plumbers.

more info needed tho., what size is the hot tank? is it lagged or plain? what temp is your boiler set to? how long is the boiler on for heating or hw a day? is there a stat on the hot tank to shut the water off? is there a blending valve on it?


can u take a pic of the hot press area and post it please

Talon.ie

Thanks for the replies.

The photo's are quite large so I've posted them here. Sorry for any blurriness.

The tank is usually lagged, but the lagging hasn't been replaced yet as they're coming back to look at the problem tonight.

There doesn't seem to be a cylinder stat.

The central heating is on for an hour and a 1/2 in the morning, previously this was enough for nice long showers

The taps were run for at least a minute and were producing hot water with no problems.


The plummer did something, "balancing" he called it. Now one of the rads isn't heating properly. I would have thought that the rads and the shower would be on completely different circuits.

Joey the lips

The pump is not over sized. 1.5 bar is fine.The cylinder looks like a 30x18 though instead of a 36 can you measure its height and width

The qualpex is not nice at the cylinder but it works ok.

Aside from that all i can see wrong is your water is being pumped faster so thats why its emptying quicker.

Talon.ie

Thanks Joey, I'll measure it when I get home.

I'm just concerned that the hot water seems to be used up in around a seventh of the time (4 minutes versus 25/30 minutes), yet there's no way (I think) that we're using 7 times the amount of water due to the pump

Joey the lips

Talon.ie wrote: »

Thanks Joey, I'll measure it when I get home.

I'm just concerned that the hot water seems to be used up in around a seventh of the time (4 minutes versus 25/30 minutes), yet there's no way (I think) that we're using 7 times the amount of water due to the pump

Bear in mind your pumping it now. What you scientifically need to check is the flow rate of the pump v's the flow rate of gravity...

This still wont really convince you.

I just cant see anything wrong but maybe someone else will

Davy

Joey the lips wrote: »

Bear in mind your pumping it now. What you scientifically need to check is the flow rate of the pump v's the flow rate of gravity...

This still wont really convince you.

I just cant see anything wrong but maybe someone else will

That was my thoughts, but if the WHB still has hot flowing from for 60 seconds, while at the same time the mixer doesn't, their is something more to it.

Joey the lips

Davy wrote: »

That was my thoughts, but if the WHB still has hot flowing from for 60 seconds, while at the same time the mixer doesn't, their is something more to it.

Not so davy as advised above if there is a flange present which there looks like there is then he will get water in the basin after the hot has stopped in the pump.

stephendevlin

Joey the lips wrote: »

Bear in mind your pumping it now. What you scientifically need to check is the flow rate of the pump v's the flow rate of gravity...

This still wont really convince you.

I just cant see anything wrong but maybe someone else will

1.5 bar = 15 Meters of head

Normal shower from the tank = 1-2 meters.

If you have a small tank fitted with a pump it can easily be emptied quick.

1.5 bar can push out about 18-20 litres a minute depending on the setup. maybe even more. 18 litres a minute is a decent powershower

Davy

Never checked the pics woops

Its still hard to tell if it is though from those angles, but guess it must be

stephendevlin

Did he put the valve in the right way around?? Hot into the hot connection and cold into the cold connection? Can sometimes be the problem with a cold shower

Irish Fire

stephendevlin wrote: »

Did he put the valve in the right way around?? Hot into the hot connection and cold into the cold connection? Can sometimes be the problem with a cold shower

Sounds like it. Turn the lever to cold and see if the water is cold, just to rule out the situation turn off the valve he has fitted at the top of the cylinder. (top left of the cylinder in your photo) don't run it too long though you might damage the pump.

Have to say don't like to see qualpex so close to the cylinder........

Talon.ie

Some answers:
The tank is 30 inches high

The valve in the shower looks ok. Turning it to cold gives cold water and turned to hot it gives nice hot water until it runs out.


I tested it again, shower still runs for 4 minutes, then starts running out of hot water.

After the shower runs totally out of hot water I turned on the taps in the basin and this produced steaming hot water for over 3 minutes before I turned it off. It never cooled down at all.

I definately get the fact that the pump will get through a lot more water than gravity, but the fact that there's still hot water available in the taps has me thinking there's something wrong

stephendevlin

Talon.ie wrote: »

Some answers:
The tank is 30 inches high

The valve in the shower looks ok. Turning it to cold gives cold water and turned to hot it gives nice hot water until it runs out.

QUOTE]

You wont know by looking at it. Is it exposed or buried in the wall?

Talon.ie

stephendevlin wrote: »

You wont know by looking at it. Is it exposed or buried in the wall?

It's buried in the wall behind the tiles

Joey the lips

Talon.ie wrote: »

Some answers:
The tank is 30 inches high

The valve in the shower looks ok. Turning it to cold gives cold water and turned to hot it gives nice hot water until it runs out.


I tested it again, shower still runs for 4 minutes, then starts running out of hot water.

After the shower runs totally out of hot water I turned on the taps in the basin and this produced steaming hot water for over 3 minutes before I turned it off. It never cooled down at all.

I definately get the fact that the pump will get through a lot more water than gravity, but the fact that there's still hot water available in the taps has me thinking there's something wrong

As i thought. Nothing wrong with the plumbing just not enough hot water being produced but in fairness to the plumber he fit the smallest pump he could.

The reason there is water in the taps is due to the extension of the surrey flange. You can remove this but you rish cavitation in the pump so you will be trading one problem for another rather than sort your existing one.

Your long term solution will be to buy a bigger cylinder.

Pete67

Or change the shower head for a high pressure one. This will reduce the volume of water consumed but still give a decent shower as the smaller nozzle size will deliver less water but at a higher pressure.

stephendevlin

Talon.ie wrote: »

It's buried in the wall behind the tiles

If you check your manual or website for the mixer you can take the front cover off the valve which will give you access to the hot cold inlet pipes

The hot pipe will be coming into the valve on the left and cold into the right.


If you have the shower on with the access panel removed you can feel test the pipes.

May not be the issue but worth a check